MALDI profiles of proteins and lipids for the rapid characterisation of upper GI-tract cancers

AimTo identify a reliable MALDI ‘cancer fingerprint’ to aid in the rapid detection and characterisation of malignant upper GI-tract disease from endoscopic biopsies.MethodsA total of 183 tissue biopsies were collected from 126 patients with or without oesophago-gastric malignancy and proteins and lipids separated by methanol/chloroform extraction. Peak intensities in the lipid and protein MALDI spectra from five types of samples (normal oesophageal mucosa from controls, normal oesophageal mucosa from patients with oesophageal adenocarcinoma, nondysplastic Barrett's oesophagus, oesophageal adenocarcinoma, normal gastric mucosa and gastric adenocarcinoma) were compared using non-parametric statistical tests and ROC analyses.ResultsNormal oesophageal and gastric tissue generated distinct MALDI spectra characterised by higher levels of calgranulins in oesophageal tissue. MALDI spectra of polypeptides and lipids discriminated between oesophageal adenocarcinoma and Barrett's and normal oesophagus, and between gastric cancer and normal stomach. Many down-regulations were unique to each cancer type whilst some up-regulations, most notably increased HNPs 1–3, were common.ConclusionsMALDI spectra of small tissue biopsies generated with this straightforward method can be used to rapidly detect numerous cancer-associated biochemical changes. These can be used to identify upper GI-tract cancers regardless of tumour location.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (232 K)Download as PowerPoint slideHighlights► Endoscopic tumour and normal biopsies collected from the upper GI-tract ► Chloroform/methanol extraction and MALDI mass spectrometry ► Multiple cancer-associated changes in lipid and protein profiles ► Rapid detection of malignancy ► HNPs 1–3 highly elevated in gastric and oesophageal adenocarcinomas